1. Field of the Invention
This invention relates to the field of processes for decaffeinating a caffeine-containing vegetable material such as tea and coffee.
2. Description of the Prior Art
There has long been a recognized demand for decaffeinated vegetable materials, particularly beverages such as coffee and tea. The customary prior art techniques for decaffeination have generally involved the use of organic solvents such as trichlorethylene or chloroform, which solvents were contacted either with the vegetable material or with an aqueous extract thereof. After sufficient caffeine was transferred to the solvent, the resultant solution of caffeine could be separated so as to allow further processing of the beverage from the decaffeinated material or extract, as the case might be.
These organic solvent-based decaffeination techniques have several disadvantages. Of particular concern to the ultimate consumer, the utilization of prior art decaffeination solvents often results in substantial loss, or denaturization, of valuable flavor and aroma constituents of the eventual beverage. Thus, decaffeination has frequently been responsible for products lacking in high quality characteristics.
Further, because the prior art solvents themselves are often detrimental, concern has been evidenced respecting contacting them with vegetable materials from which comestibles are to be produced. This concern has resulted in the development of complex and stringent processing techniques in order to insure solvent separation from the eventual products.